title: Evolutionary history and phylogenetic relationship between Auxis thazard and Auxis rochei inferred from COI sequences of mtDNA.
abstract: Tunas of the genus Auxis are cosmopolitan species and the smallest members of the tribe Thunnini, the true tunas. In the present study, COI sequences of mtDNA were employed to examine the evolutionary history and phylogenetic relationship between A. thazard and A. rochei. A total of 29 COI sequences were retrieved from NCBI. Historic demographic analyses of sequence data showed that A. thazard has undergone sudden population expansion in the past while population size of A. rochei has been remain constant for long period. Non-significant value of Tajimas's D (P = 0.22400) and Fu's FS (P = 0.21400) test fail to reject the null hypothesis of neutral evolution for A. rochei. Phylogenetic analyses of nucleotide sequences demonstrated separate clusters for both species and are strongly supported by 98% bootstrap value. The results of the present study suggest the recent founding of A. thazard in world ocean while A. rochei represents the ancestral species.
authors.affiliation: Biological Oceanography Division (BOD), National Institute of Oceanography (NIO), Dona Paula, Goa 403004, India.
authors.forename: Girish
authors.initials: G
authors.lastname: Kumar
authors.forename: Swaraj Priyaranjan
authors.initials: SP
authors.lastname: Kunal
authors.forename: S K
authors.initials: SK
authors.lastname: Shyama
mesh_terms: D000818:Animals; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics*; D019143:Evolution, Molecular; D029941:Fish Proteins / Q000235:genetics; D010802:Phylogeny; D013045:Species Specificity; D014413:Tuna / Q000145:classification / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial; D029941:Fish Proteins
keywords: Auxis rochei; Auxis thazard; COI sequences; bioinformatics; diagnostic markers; evolutionary history; mtDNA; nucleotide sequences; phylogenetic relationship; population expansion; tuna